It is sometimes necessary to remove an automobile or truck wheel and mount a spare wheel in its place. These are heavy, awkward to lift, and dirty. A person changing a tire is likely to soil his or her hands and clothing.
In changing a tire, removal of the wheel is effected simply by jacking up the respective axle so the tire will clear the ground, removing the wheel nuts, and dropping the wheel to the ground. But, replacing the wheel requires lifting it up to the axle level with the operator's arms extending inside the wheel well, while turning it in mid-air to register the wheel holes with the bolt studs.
Tools have been proposed to simplify this lifting and turning operation, but none has been entirely satisfactory.
A common feature of many of these prior art tools is that they have a stud-receiving socket on the end of a rod or shank which functions as a pilot bar. To mount or remount a wheel, the rod or shank is inserted through a bolt hole in the wheel, with the socket engaging the corresponding bolt stud on the hub. By lifting the other end of the rod, leverlike, the wheel can be elevated and guided onto the bolt studs on the hub.
In some of these prior art tools, the end of the socket is undercut on the bottom so that only a relatively small arcuate upper lip can engage the bolt stud to lever the wheel upwardly into place. Examples of such undercut constructions are shown in Schoenwerk U.S. Pat. No. 1,649,130 issued in 1927 on Tool For Mounting Disc Wheels, Patterson U.S. Pat. No. 1,999,206 issued in 1935 on Wheel Mounting Tool, and Freet U.S. Pat. No. 3,364,558 issued in 1968 on Wheel-Mounting Tool. A serious disadvantage of this undercut construction is that the rotational orientation of the tool is critical. It must be turned so the arcuate upper lip on the socket hooks over the top of the bolt stud, otherwise it slips off, possibly dropping the wheel on the operator. It is difficult to keep the tool precisely upright because the wheel covers the hub and obscures the operator's view of the socket.
In some other prior art tools, there is a universal or bolt joint between the tool shank and the socket. Examples are shown in Meyers U.S. Pat. No. 1,494,269 issued in 1924 on Tool For Mounting Disc Wheels, and Tarter et al. U.S. Pat. No. 3,389,453 issued in 1968 on Tire Installation Tool. A major disadvantage of this universal joint construction is that it is unstable and likely to slip off the bolt stud during the wheel lifting operation.
One proposal for such a tool is shown in Patterson U.S. Pat. No. 1,969,233 issued in 1934 on Wheel Mounting Tool. FIG. 4 of that patent shows a continuous circumferential inwardly extending retaining flange at the mouth of the socket. This is intended to engage the bolt stud thread to keep the tool from slipping off during the wheel lifting operation. Because the flange is at right angles to the axis of the socket, it will tend to ride on the tips of the bolt stud threads if the pilot rod and bolt stud are coaxially aligned. To get some effective engagement of the socket flange in the space between the bolt stud threads, the tool handle must be cocked out of alignment with the bolt stud. Further, the flange is made very thin resembling a knife edge to help it fit between the threads. This is a disadvantage because this sharp edge interferes with smooth withdrawal of the socket after the wheel is lifted into place.
There is a need for such a wheel mounting tool which will positively engage the space between threads in a bolt stud during the wheel mounting operation without peculiarly orienting the tool shank, and which is easily released from the bolt stud threads after the wheel is lifted into place.